China is subtly pressuring exiled Cambodian resistance leader Prince Norodom Sihanouk to adopt a harder line in peace talks with the Vietnamese-backed Cambodian regime, diplomats said Tuesday. Meanwhile, the prince is urging China, the main arms supplier of the Cambodian rebel forces, to firmly back his more conciliatory efforts to negotiate a peace for the war-ravaged nation, according to Asian and Western diplomats.

Disagreement between Prince Sihanouk, who officially resigned as the resistance coalition president Jan. 30, and his Chinese patrons was evident in official press accounts of the prince's meeting with Communist Party chief Zhao Ziyang on Monday.

``The Chinese haven't been at all happy with Sihanouk's talks'' with the pro-Vietnamese Phnom Penh regime, one Western diplomat said. The second round of talks was held in France Jan. 20-21. The disagreement involves three issues, all central to the peace talks:

Peking's chief concern is that any talks achieve a quick end to Vietnam's nine-year-old occupation of neighboring Cambodia. China views Vietnam's powerful military as a major strategic threat to its southern flank.

``China doesn't want an Indochina dominated by a militarily aggressive Vietnam, and certainly not by a Soviet-supported Vietnam,'' said the Western diplomat.

China invaded Vietnam in 1979 in retaliation for Hanoi's occupation of Cambodia in late 1978, and the two erstwhile comrades-in-arms fought a short border war. Border skirmishes have erupted sporadically ever since.

In a meeting with Sihanouk Monday, Mr. Zhao stressed that China will continue supplying the Cambodian guerrilla forces as long as any of the estimated 100,000 to 140,000 Vietnamese occupation troops remain in Cambodia, the official new China News Agency reported. Zhao's remarks strongly indicate Peking's opposition to a compromise on the timing of Vietnam's troop pullout accepted by Sihanouk at the second round of talks. Sihanouk reportedly then agreed to join in a provisional coalition government after only two-thirds of the Vietnamese troops quit Cambodia.

A second point of disagreement is whether a new Cambodian government would include only two parties - Sihanouk's and the pro-Vietnamese regime represented by Hun Sen - or whether it must also incorporate Sihanouk's two resistance partners: the communist Khmer Rouge and the noncommunist Khmer People's National Liberation Front.

Last month, Sihanouk reportedly agreed as a last resort to split with his partners and join Hun Sen, premier of the Hanoi-backed People's Republic of Kampuchea (Cambodia or PRK), in a provisional government on condition that the PRK is disolved first. Hun Sen rejected that condition, and demanded the disbanding of the Khmer Rouge, which commands an estimated 30,000 Cambodian guerrillas.

Peking, however, has refused to relinquish support for the Khmer Rouge, which was responsible for the deaths of uncountable Cambodians during its 1975 to 1978 rule.

In talks with Sihanouk on Monday, Zhao clearly indicated that China expects any coalition government to include all four factions in Cambodia, implying Peking will not stand for the Khmer Rouge's exclusion.

In order to restrain Vietnam, China has long sought to forge greater unity within the loosely grouped Cambodian resistance government, which has been torn by deep factional infighting. Chinese leaders are also displeased with Sihanouk's resignation as president of the UN-recognized coalition, and are likely to encourage him to reconsider.

The prince withdrew from the divisive rebel coalition in order to gain flexibility in negotiating with officials of the Hanoi-backed Phnom Penh regime, an Asian diplomat said.

Sihanouk, Cambodia's head of state from 1941 to 1970, also intends to signal his willingness to push forward with the talks, the diplomat said.

``Sihanouk is telling the Chinese: `I want to negotiate a peace, you must give me all the confidence you have. Otherwise you will be presented with a fait accompli,''' he said.